686778642639360 has 6400 divisors, whose sum is σ = 2932271522611200. Its totient is φ = 152614836633600.

The previous prime is 686778642639347. The next prime is 686778642639371. The reversal of 686778642639360 is 63936246877686.

686778642639360 is a `hidden beast` number, since 6 + 8 + 6 + 77 + 86 + 4 + 26 + 393 + 60 = 666.

It is a super-3 number, since 3×686778642639360³ (a number of 45 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 686778642639360.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 639 ways as a sum of consecutive naturals, for example, 7716613962196 + ... + 7716613962284.

It is an arithmetic number, because the mean of its divisors is an integer number (458167425408).

Almost surely, 2^{686778642639360} is an apocalyptic number.

686778642639360 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 686778642639360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1466135761305600).

686778642639360 is an abundant number, since it is smaller than the sum of its proper divisors (2245492879971840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

686778642639360 is a wasteful number, since it uses less digits than its factorization.

686778642639360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305 (or 280 counting only the distinct ones).

The product of its (nonzero) digits is 15801827328, while the sum is 81.

The spelling of 686778642639360 in words is "six hundred eighty-six trillion, seven hundred seventy-eight billion, six hundred forty-two million, six hundred thirty-nine thousand, three hundred sixty".